The completion of Phase III construction in B Plant will provide facilities to meet certain common needs of departmental Waste Management and Fission Product programs. This is an estimate of the total and unit costs of operation in these facilities on a `goin concern` basis, recognizing full well the highly tentative nature of information available with respect to staffing, process rates, equipment, etc., approximately 3 to 4 years in advance of operations. It is planned that this document serve as an operating cost guideline during the interim period, subject to periodic revision as more firm data of significant cost impact becomes available. This review covers those functions performed within B Plant proper plus a PAW feed material preparation function tentatively planned for Purex head end for convenience purposes. Feed material streams from supernatant and sludge removal functions are considered F.O.B. B Plant. No staffing or costs have been included for tank farm activities or the 200 North storage function. Cesium and strontium costs include processing to a solid and packaging in a high integrity container compatible with final confinement requirements. Staffing is provided to perform a peroxyacetate strike or similar function for the cerium-rare earth fraction, but additional study would …